Data centers route massive quantities of data. Currently, data centers may have a throughput of about 5-7 terabytes per second, which is expected to drastically increase in the future. Electrical packet switches are used to route data packets in these data centers. Electrical packet switches switch or route packets based on a packet header with inter-stage buffering. The buffering can overflow, causing packet loss and the need for packet retransmission.
Racks of servers, storage, and input-output functions may contain top of rack (TOR) packet switches which combine packet streams from their associated servers and/or other peripherals into a lesser number of very high speed packet streams per TOR switch. These packet streams are routed to the packet switching core switch resource. Also, TOR switches receive the returning switched streams from that resource and distribute them to servers within their rack. There may be 4×40 Gb/s streams from each TOR switch to the core switching resource, and the same number of return streams. There may be one TOR switch per rack, hundreds to ten thousands of racks, and hence hundreds to ten thousands of TOR switches in a data center.
There has been a massive growth in data center capabilities, leading to massive electronic packet switching structures, which are becoming more complex, difficult and expensive to implement. There is a desire for alternative to this approach, such as photonic packet switching.